Electric power control system and process

ABSTRACT

A method and apparatus for controlling electric power supplied to one or more electrical devices from a power source are disclosed. Measurements of the supplied electricity are detected. Estimated deviant voltage levels that the supplied electricity will not drop below or exceed as a result of varying electrical consumption by the one or more electrical devices is computed based on a predetermined confidence level and the detected measurements. A voltage level output of the electricity supplied to the electrical device is adjusted based on the computed deviant voltage level.

CROSS-REFERENCE TO RELATED APPLICATIONS

These claimed embodiments relate to a method for regulating The presentapplication is related to, claims the earliest available effectivefiling date(s) from (e.g., claims earliest available priority dates forother than provisional patent applications; claims benefits under 35 USC§119(e) for provisional patent applications), and incorporates byreference in its entirety all subject matter of the following listedapplication(s); the present application also claims the earliestavailable effective filing date(s) from, and also incorporates byreference in its entirety all subject matter of any and all parent,grandparent, great-grandparent, etc. applications of the followinglisted application(s):

1. United States patent application entitled ELECTRIC POWER CONTROLSYSTEM AND EFFICIENCY OPTIMIZATION PROCESS FOR A POLYPHASE SYNCHRONOUSMACHINE, naming David G. Bell as inventors, filed substantiallycontemporaneously herewith.

2. U.S. patent application Ser. No. 11/397,091, entitled ELECTRICALPOWER DISTRIBUTION CONTROL SYSTEMS AND PROCESSES, naming David G. Bell;Thomas L Wilson; and Kenneth M. Hemmelman as inventors, filed Apr. 4,2006.

TECHNICAL FIELD

These claimed embodiments relate to a method for regulating electricpower being supplied to one or more electrical or electronic loads andmore particularly to adjusting voltage levels of power provided to theelectrical or electronic device(s) based on estimates determined fromthe electrical or electronic device(s) consumption.

BACKGROUND OF THE INVENTION

A method and apparatus for regulating electric power being supplied toone or more electrical or electronic device(s) is disclosed.

When supplying power to large industrial devices that consume atremendous amount of electrical power, several needs compete and must besimultaneously considered in managing electrical power distribution. Afirst concern has to do with maintaining delivered electrical powervoltage levels within predetermined limits. A second concern relatesimproving overall efficiency of electrical power usage and distribution.A third concern relates to these and other concerns in light of changingelectrical loading of the system and variations in the character of theloading so that the voltages do not decrease to such a level that thedevices shut down or function improperly.

One way to accommodate changes in electrical loading is to set presetthreshold levels at which the voltage level of the distribution systemchanges. When the system detects a change in the voltage level, a tapchange is initiated (on a multiple-tap transformer) resulting in asystem voltage change. A drawback of this system is that the tap maychange frequently thus increasing the tap mechanism failure rate.Further the system voltage level may drop suddenly so the presetthreshold levels must be set sufficiently high to prevent shutdownresulting in system inefficiencies.

SUMMARY OF THE INVENTION

In one implementation a method is disclosed that continuously detectsmeasurements of electrical power supplied to one or more electricaldevices from a power source. Estimated deviant voltage levels that thesupplied electricity will not drop below or exceed as a result ofvarying electrical consumption by the one or more electrical devices arecontinuously computed. The deviant voltage levels may be computed basedon a predetermined confidence level and specific properties of theeffects on measured voltage due to varying consumption computed from thedetected measurements. A voltage level output of the electricitysupplied to the electrical device may be adjusted based on the computeddeviant voltage level. In an additional implementation, the deviantvoltage levels may be based on measurements obtained from each of thethree phases in a three-phase electric power distribution system. Avoltage level supplied to the three-phase distribution system may beadjusted by a voltage regulator capable of setting three-phase voltages.

In another implementation, a system is disclosed including an electronicmeter, a processor and a voltage regulator device. The electronic metercontinuously detects measurements of electricity supplied to one or moreelectrical devices from a power source. The processor is incommunication with the electronic meter to continuously computeestimated deviant voltage levels that the supplied electricity will notdrop below or exceed as a result of varying electrical consumption bythe electrical device and the detected measurements. The voltageregulator device receives a signal from the processor to adjust avoltage level output of the electricity supplied to the electricaldevice from the power source based on the computed deviant voltagelevel.

In addition, a computer readable storage medium comprising instructionsis disclosed. The instructions when executed by a processor continuouslydetect measurements of electricity supplied to one or more devices froma power source. The instructions also continuously compute estimateddeviant voltage levels that the supplied electricity are not expected todrop below or to exceed with some level of confidence as a result ofvarying electrical consumption by the one or more electrical devices. Inone implementation the deviant voltage level is computed based on apredetermined confidence level and the detected measurements. Theinstructions also provide a signal to adjust a voltage level output ofthe electricity supplied to the one or more electrical devices based onthe computed estimated deviant voltage level.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description is described with reference to the accompanyingfigures. In the figures, the left-most digit(s) of a reference numberidentifies the figure in which the reference number first appears. Theuse of the same reference number in different figures indicates similaror identical items.

FIG. 1 is a simplified schematic diagram of a voltage control system forregulating power;

FIG. 2 is a simplified schematic diagram of a voltage signal processingelement shown in FIG. 1 that processes measured voltage signals toprovide a selected voltage signal for tap regulation;

FIG. 3 is a simplified schematic diagram of a voltage controller shownin FIG. 1;

FIG. 4 is a flow chart of a process for determining a voltage adjustmentdecision by the voltage controller shown in FIG. 3;

FIG. 5 is a diagram illustrating an exemplary elastic decisionboundaries used by the voltage control system; and

FIG. 6 is a diagram illustrating a typical probability distribution ofthe voltage control system that is used to select a weighting factorthat is used in estimating voltage deviations.

DETAILED DESCRIPTION

Referring to FIG. 1 there is shown a voltage control system 100 havingpower source 101 connected via a subsystem transmission bus 102 and viasubstation transformer 104 to a voltage regulating transformer 106.Voltage regulating transformer 106 is controlled by voltage controller108 with regulator interface 110. Voltage regulating transformer 106 isoptionally coupled on primary distribution circuit 112 via optionaldistribution transformer 114 to secondary utilization circuits 116 andto one or more electrical or electronic devices 119. Voltage regulatingtransformer 106 has multiple tap outputs (not shown) with each tapoutput supplying electricity with a different voltage level. Theillustrated system described herein may be implemented as either asingle-phase or three-phase distribution system.

In an AC Power distribution system and as used herein voltage may begenerally is referred to as an “RMS Voltage”. The regulating transformer106 is typically one of two basic types: (1) a multi-tap autotransformer(single or three phase), which are used for distribution; or (2) on-loadtap changer (three phase transformer), which is integrated into asubstation transformer and used for both transmission and distribution.

Monitoring devices 118 a-118 n are coupled through optional potentialtransformers 120 a-120 n to secondary utilization circuits 116.Monitoring devices 118 a-118 n continuously detects measurements andcontinuous voltage signals of electricity supplied to one or moreelectrical devices 119 connected to circuit 112 or 116 from a powersource 101 coupled to bus 102. Monitoring devices 118 a-118 n arecoupled through communications media 122 a-122 n to voltage controller108.

Voltage controller 108 continuously computes estimated deviant voltagelevels that the supplied electricity will not drop below or exceed as aresult of varying electrical consumption by the one or more electricaldevices. The deviant voltage levels are computed based on apredetermined confidence level and the detected measurements (asexplained in more detailed herein). Voltage controller 108 includes avoltage signal processing circuit 126 that receives sampled signals frommetering devices 118 a-118 n. Metering devices 118 a-118 n process andsample the continuous voltage signals such that the sampled voltagesignals are uniformly sampled as a time series that are free of spectralaliases. Such metering devices having this process and sample capabilityare generally commercially available.

Voltage signal processing circuit 126 receives signals viacommunications media from metering devices 118 processes the signals andfeeds them to voltage adjustment decision processor circuit 128.Although the term “circuit” is used in this description, the term is notmeant to limit this disclosure to a particular type of hardware ordesign, and other terms known generally known such as the term“element”, “hardware”, “device” or “apparatus” could be usedsynonymously with or in place of term “circuit” and may perform the samefunction. Adjustment decision processor circuit 128 determines a voltagelocation with respect to a defined decision boundary and sets the tapposition and settings in response to the determined location. Morespecifically adjustment decision processing circuit 128 in voltagecontroller 108 computes a deviant voltage level that is used to adjustthe voltage level output of electricity supplied to the electricaldevice. In other words, one of the multiple tap settings of regulatingtransformer 106 is continuously selected by voltage controller 108 viainterface 110 to supply electricity to the one or more electricaldevices based on the computed deviant voltage level. Regulator interface110 may include a processor controlled circuit for selecting one of themultiple tap settings in voltage regulating transformer 106 in responseto an indication signal from voltage controller 108.

As the computed deviant voltage level changes other tap settings (orsettings) of regulating transformer 106 are selected by voltagecontroller 108 to change the voltage level of the electricity suppliedto the one or more electrical devices.

Referring to FIG. 2, voltage signal processing element 200 is shownhaving processing elements 202 a-202 n coupled to minimum selectorcircuit 204. Each of the processing elements 202 a-202 n receives ontheir respective input terminals a measured voltage signal from arespective metering device 118 a-118 n (FIG. 1). Processing elements 202a-202 n processes the measured signal (as described herein) andgenerates a processed voltage signal on their output terminals 206 a-206n respectively. Minimum selector circuit 204 selects the processedvoltage signal having the minimum voltage and provides the selectedsignal to the voltage adjustment decision processor circuit 128 forfurther processing in tap setting regulation.

Processing elements 202 a-202 n are identical and thus only one element,202 a will be described. Processing element 202 a includes threeparallel processing paths that are coupled to summation circuit 210.Each of the processing elements receives sampled time series signalsfrom metering devices 118 a-118 n.

In the first path, a low pass filter circuit 212 receives the measuredvoltage signal, applies a low pass filter to the signal and feeds thelow pass filtered signal to delay compensate circuit 214 where thesignal or an estimate of the signal is extrapolated in time such thatthe delay resulting from the low pass filtering operation is removed andthen fed to summation circuit 210.

In the second path, a linear detrend circuit 220 receives the measuredvoltage signal, and removes any linear trends from the signal. Theresulting signal, having zero mean and being devoid of any change in itsaverage value over its duration, is then applied to dispersion circuit222 where a zero mean dispersion is estimated for the signal. The zeromean dispersion estimated signal is fed to low pass filter circuit 224that applies a low pass filter to the signal. The filtered signal isthen fed to delay compensation circuit 226 where the filtered signal oran estimate of the filtered signal is extrapolated in time such that thedelay resulting from the low pass filtering operation is removed. Aweighting factor 606 is shown in FIG. 6 and is described in connectiontherewith. Weighting factor 606 is derived from a specified confidencelevel as described herein and is applied to the signal output fromelement 226 before being fed as a delay compensated signal to summationcircuit 210.

In the third path, a band pass filter circuit 230 receives the measuredvoltage signal, and applies a band pass filter to the signal. Thefiltered signal is then applied to an envelope circuit 232 where thesignal is formed into a peak envelope with specified peak decaycharacteristics. The peak envelope signal is fed to low pass filtercircuit 234 that applies a low pass filter to the signal to provide afiltered smooth peak envelope voltage signal, and feeds the signal todelay compensation circuit 236 where the filtered smooth peak envelopevoltage signal or an estimate thereof is extrapolated in time such thatthe delay resulting from the low pass filtering operation is removedbefore being fed to as a delay compensated signal to summation circuit210.

Example Voltage Controller Architecture

In FIG. 3 are illustrated selected modules in Voltage Controller 300using process 400 shown in FIG. 4. Voltage Controller receives Signalsfrom voltage signal processing circuit 126 and feeds signals toregulator interface 110. Voltage Controller 300 has processingcapabilities and memory suitable to store and executecomputer-executable instructions. In one example, Voltage Controller 300includes one or more processors 304 and memory 312.

The memory 322 may include volatile and nonvolatile memory, removableand non-removable media implemented in any method or technology forstorage of information, such as computer-readable instructions, datastructures, program modules or other data. Such memory includes, but isnot limited to, RAM, ROM, EEPROM, flash memory or other memorytechnology, CD-ROM, digital versatile disks (DVD) or other opticalstorage, magnetic cassettes, magnetic tape, magnetic disk storage orother magnetic storage devices, RAID storage systems, or any othermedium which can be used to store the desired information and which canbe accessed by a computer system.

Stored in memory 322 of the Voltage Controller 300 may include a realtime operating system 314, an I/O controller 316, a confidence store318, and an adjustment decision application 320. Real time operatingsystem 314 may be used by adjustment decision application 320 to operatecontroller 300. I/O controller may provide drivers for Voltagecontroller to communicate with Voltage signal processor or regulatorinterface. A confidence store 318 may include preconfigured parameters(or set by the user before or after initial operation) such a confidencevalues, electrical device operating parameters, voltage levels,deadband, setpoint values and probabilities. Such values may be updatethrough an interface with the user directly to the voltage controller(not shown). Details of the adjustment decision application and processare described in FIG. 4.

Illustrated in FIG. 4, is a process 400 for determining a voltageadjustment decision. The exemplary process in FIG. 4 is illustrated as acollection of blocks in a logical flow diagram, which represents asequence of operations that can be implemented in hardware, software,and a combination thereof. In the context of software, the blocksrepresent computer-executable instructions that, when executed by one ormore processors, perform the recited operations. Generally,computer-executable instructions include routines, programs, objects,components, data structures, and the like that perform particularfunctions or implement particular abstract data types. The order inwhich the operations are described is not intended to be construed as alimitation, and any number of the described blocks can be combined inany order and/or in parallel to implement the process. For discussionpurposes, the processes are described with reference to FIG. 4, althoughit may be implemented in other system architectures.

Referring to FIG. 4, a process 400 is shown for determining a voltageadjustment decision by voltage adjustment decision processor circuit 128using the processor and modules shown in FIG. 3. In the process, theselected voltage signal is received from the voltage signal processingelement 200 (FIG. 2) in block 402. In block 404, a determination is madeof the location of the voltage with respect to defined boundarydecisions. A graph of exemplary voltage locations and their boundariesis shown in FIG. 5. The decision boundaries were preset based oncharacteristics of the electrical and electronic devices comprising theloads and confidence levels as discussed herein.

If a determination is made that the received selected voltage is below alower boundary, an assert voltage increase is executed in block 406.When a voltage increase assertion is executed an increase indicationsignal is sent to voltage regulating transformer 106 via the regulatorinterface 110 to increase the tap setting, thereby increasing thedelivered voltage.

If a determination is made that the received selected voltage is abovethe lower bound and below the lower deadband, an increment voltageincrease integrator is executed in block 408. If a determination is madethat the received selected voltage is above the lower deadband and belowthe setpoint, a decrement voltage increase integrator is executed inblock 410.

If a determination is made that the received selected voltage is belowthe upper deadband and above the setpoint, a decrement voltage increaseintegrator is executed in block 412. If a determination is made that thereceived selected voltage is below the upper bound and above the upperdead band, an increment voltage decrease integrator is executed in block414.

If a determination is made that the received selected voltage is aboutthe upper bound, an assert voltage decrease is executed in block 416.When an assert voltage decrease is executed a decrease indication signalis sent to voltage regulator transformer via the regulator interface 110to decrease the tap voltage.

After the assert voltage increase is executed in block 406, a confirmvoltage increase is executed in block 420. After the assert voltagedecrease is executed in block 416, a confirm voltage decrease isexecuted in block 422. After executing the confirm voltage increase inblock 420 and confirm voltage decrease in block 422, a set allintegrators to zero is executed in block 424.

After executing the increment voltage increase integrator in block 408and the decrement voltage increase integrator in block 410, a setvoltage decrease integrator to a zero is executed in block 426. Afterexecuting the decrement voltage decrease integrator in block 412 and theincrement voltage decrease integrator in block 414, a set voltageincrease integrator to a zero is executed in block 428.

After executing set voltage decrease integrator to zero is executed inblock 426, a determination is made in block 440 whether the voltageincrease integrator exceeds a predetermined limit. If the voltageincrease integrator exceeds the predetermined limit, then a voltageincrease is asserted in block 406 and confirmed in block 420. If thevoltage increase integrator does not exceed the predetermined limit,then the process ends in block 450.

After executing set voltage increase integrator to zero is executed inblock 428, a determination is made in block 432 whether the voltagedecrease integrator exceeds a predetermined limit. If the voltageincrease integrator exceeds the predetermined limit, then a voltagedecrease is asserted in block 416 and confirmed in block 422. If thevoltage decrease integrator does not exceed the predetermined limit,then the process ends in block 450.

Confirmation of a voltage increase or decrease may be implemented bydetecting a step change in one or more voltage(s) measured bycorresponding metering device(s) 118 a-118 n. An exemplary method fordetection of such a step change involves computation of the statisticalmoments of a voltage time series segment which is expected to manifest astep change, and comparing those moments with those for an ideal stepchange such as the Heaviside step function. This method of momentmatching is described, for example, in a different context by Tabatabai,A. J. and Mitchell, O. R., “Edge Location to Subpixel Values in DigitalImagery”, IEEE Transactions on Pattern Analysis and Machine IntelligenceVolume PAMI-6, No. 2, pp 188-210, 1984. The magnitude of the step changethus computed may then be compared to that expected by the change in thevoltage regulator tap setting to confirm that the voltage change hasoccurred.

Once the voltages are confirmed in blocks 420 and 422 all integratorsare set to zero in block 424 and the process ends in bock 450.

If the voltage decrease integrator does not exceed the predeterminedlimit, and after setting all integrators to zero in block 448, theprocess ends in block 450. After ending in block 450 the process mayrepeat again upon receiving the selected signal from the voltageprocessor in block 402.

Referring to FIG. 5, there is shown graph 500 illustrating exemplaryelastic tap decision boundaries used by the process described in FIG. 4.On the x-axis of graph 500 are the salient voltages and on the y-axis isshown selected integral weights assigned to the voltage regions. A setpoint voltage 502 is indicated at the center voltage level, and a deadband 504 is assigned at equal voltage displacements from the set pointvoltage.

An upper bound 508 and lower bound 510 are outside the deadband and aredefined based on the predetermined confidence level using the formulasdescribed herein. The forward integration regions are defined as theregion between the deadband and the upper bound, or between the deadbandand the lower bound. The forward integral weights are applied in theseregions. The reverse integration regions are defined as the regionsbetween the dead band and the set point voltage 502.

Exemplary Tap Response to Voltage Changes on Curved Decision Boundaries

In one implementation when the received selected voltage signal from thevoltage processor is at a selected minimum voltage at Point ‘A’, thenonlinear integral associated with a tap decrease decision will beincremented. If the received selected voltage signal remains within theindicated region, eventually a voltage tap decrease will be asserted.Similarly, when the selected minimum voltage appears at Point ‘AA’, thenonlinear integral associated with a tap increase decision will beincremented, eventually resulting in a voltage tap increase assertion.

On the other hand if when the received selected voltage signal from thevoltage processor is at a selected minimum voltage at Point ‘B’, thenonlinear integral associated with a tap increase decision will bedecremented and eventually nullifying the pending tap decision.Similarly, when the selected minimum voltage appears at Point ‘BB’, thenonlinear integral associated with a tap decrease decision will bedecremented, eventually nullifying the pending tap decision.

Background for Dispersion and Variance

For a subject time series obtained by uniform sampling of a randomprocess, comprising sample values:

x_(k), 1≦k≦n, one may estimate the scale of the sampled time series aseither the sample variance or the sample dispersion, depending on theproperties of the random process from which the samples are obtained.

First, an estimate of the statistical location, often referred to as theaverage or mean, is required. For some non-gaussian random processes,the sample mean does not suffice for this purpose, motivating the use ofthe median or other robust measures of sample location. In the formulasthat follow, we shall designate the location estimate as x.

A class of non-gaussian random processes is characterized byheavy-tailed probability densities, which are often modeled foranalytical purposes as alpha-stable distributions and are thus referredto as alpha-stable random processes. For an exemplary reference on theapplication of such distributions in signal processing, see: Nikias, C.L. and Shao, M., “Signal Processing with Alpha-Stable Distributions andApplications”, John Wiley & Sons, 1995. For time series sampled fromnon-gaussian alpha-stable random processes, one may estimate the scaleas the sample dispersion:

${d = {\mathbb{e}}^{\frac{1}{n}{\sum\limits_{k = 1}^{n}{\ln{{x_{k} - \overset{\_}{x}}}}}}},{{{for}\mspace{14mu} x_{k}} \neq \overset{\_}{x}}$

For time series sampled from gaussian random processes, one may estimatethe scale as the sample variance:

$s = {\frac{1}{n - 1}{\sum\limits_{k = 1}^{n}\left( {x_{k} - \overset{\_}{x}} \right)^{2}}}$

The choice of the location and scale estimates may be motivated by theproperties of the subject random process, which can be determined, forexample, by examination of estimates of the probability density of therandom process.

Weighting Factors and Integrals Formulas for Use with a Voltage ControlProcessor

The deviation voltage used in the decision boundary integrals iscomputed as the difference between the selected minimum voltage and thevoltage setpoint:

Δv=v_(min)−v_(set)

The computation of the weighting factors requires that the parametersfor the weighting functions be defined and available to the voltagecontroller processor. The following example will use the first-ordersigmoid function as the nonlinear weighting function but many others maybe applied to achieve different integrating behavior; for example,trigonometric functions, linear or trapezoidal functions, polynomialfunctions, spine fitting functions, or exponential functions of anyorder could serve here. In the following definitions, specificsubscripts will be used to denote the region of application of thedefined quantity.

subscript a shall indicate the region above the setpoint voltage v_(set)

subscript b shall indicate the region below the setpoint voltage v_(set)

subscript f shall indicate quantities used in the forward (incrementing)integrals

subscript r shall indicate quantities used in the reverse (decrementing)integrals

Thus, define v_(af), v_(bf) as the inflection points of the sigmoidfunctions for the weights for the upper (voltage decrease) and lower(voltage increase) forward integrals, respectively.

Similarly, define v_(ar), v_(br) as the inflection points of the sigmoidfunctions for the weights for the upper (voltage decrease) and lower(voltage increase) reverse integrals, respectively.

Define 2Δv_(d) as the magnitude of the voltage deadband, symmetricalaround the voltage setpoint.

Assigning the quantity β as the slope parameter for the first-ordersigmoid and the quantity ω as the voltage corresponding to the locationof the inflection point, we can define the nonlinear weighting functionsfor the four regions of interest:

ω_(af)=[1+e^(β) ^(af) ^((v) ^(af) ^(−v) ^(min) ⁾]⁻¹ is the upper forwardintegral weight function

ω_(ar)=[1+e^(β) ^(ar) ^((v) ^(min) ^(−v) ^(ar) ⁾]⁻¹ is the upper reverseintegral weight function

ω_(bf)=[1+e^(β) ^(bf) ^((v) ^(min) ^(−v) ^(bf) ⁾]⁻¹ is the lower forwardintegral weight function

ω_(br)=[1+e^(β) ^(br) ^((v) ^(br) ^(−v) ^(min) ⁾]⁻¹ is the lower reverseintegral weight function

The upper voltage adjustment decision integral may now be written as

$\Psi_{a} = {\frac{1}{T_{a}}{\int{\left( {\omega_{af}\Delta\; v{_{{\Delta\; v} > {v_{set} + v_{d}}}{{- \omega_{ar}}\Delta\; v}}_{{\Delta\; v} < {v_{set} + v_{d}}}} \right){\mathbb{d}t}}}}$

and the lower voltage adjustment decision integral as

$\Psi_{b} = {{- \frac{1}{T_{b}}}{\int{\left( {\omega_{bf}\Delta\; v{_{{\Delta\; v} < {v_{set} - v_{d}}}{{- \omega_{br}}\Delta\; v}}_{{\Delta\; v} > {v_{set} - v_{d}}}} \right){\mathbb{d}t}}}}$

The voltage controller then asserts a voltage decrease signal (causingthe voltage regulating transformer 106 to tap down) if eitherΔv>v_(a)−v_(set) or Ψ_(a)>v_(a)−v_(set); in either case, the controllerfurther determines that the ‘tap down’ operation will not cause thevoltage regulating transformer 106 to exceed the lowest tap positionpermitted by the regulator interface device.

Similarly, the voltage controller then asserts a voltage increase signal(causing the voltage regulating transformer 106 to tap up) if eitherΔv<v_(b)−v_(set) or Ψ_(b)<v_(b)−v_(set); in either case, the controllerfurther determines that the ‘tap up’ operation will not cause thevoltage regulating transformer 106 to exceed the highest tap positionpermitted by the regulator interface device.

Referring to FIG. 6, diagram 600 is shown having cumulative probabilitydistribution curve 602 illustrating a typical probability distributionof the voltage control system that is used to select a weighting factorthat is used in estimating voltage deviations. The x-axis corresponds toa unit random variable and the y-axis corresponds to a probability. Inone implementation a “Tail Probability” 604 or (1−p) is computed usingthe formula “p=(1−a)/2”, where “a” is the specified confidence level and“p” is the tail probability. A “Weighting Factor” 606 is the value ofthe unit random variable (also generally referred to as “normalized”) aslocated on the Probability Distribution corresponding to the TailProbability. Although a typical probability distribution is shown, theparticular probability distribution that is applied may vary dependingon the properties of the electrical load for the electrical orelectronic devices.

From the foregoing, it is apparent the description provides systems,processes and apparatus which can be utilized to monitor and manageelectrical power distribution. Further, the disclosed systems, processesand apparatus permit power conservation by maintaining deliveredvoltages near levels that optimize the efficiency of the connectedelectrical and electronic devices and also can provide more robust powerdelivery under inclement power system loading conditions. In addition,the systems, processes and apparatus of the present system are costeffective when compared with other power management devices. In contrastto prior art systems, the present systems, processes and apparatusprovide infinite variability of system parameters, such as multiple,different delivered voltage levels, within predetermined limits. Forexample, all users can be incrementally adjusted up or down together, orsome users may be adjusted to a first degree while other users areadjusted to another degree or to separate, differing degrees. Suchadvantageously provides new flexibility in power distribution control,in addition to providing new methods of adjustment.

While the above detailed description has shown, described and identifiedseveral novel features of the invention as applied to a preferredembodiment, it will be understood that various omissions, substitutionsand changes in the form and details of the described embodiments may bemade by those skilled in the art without departing from the spirit ofthe invention. Accordingly, the scope of the invention should not belimited to the foregoing discussion, but should be defined by theappended claims.

What is claimed is:
 1. A method comprising: detecting, by an electronicmeter, measurements of electricity supplied to one or more electricaldevices via a voltage regulator; computing, by a voltage controller, anestimated deviant voltage level based on varying electrical consumptionby the one or more electrical devices, the estimated deviant voltagelevel computed based on a predetermined confidence level and themeasurements, wherein the predetermined confidence level corresponds toa probability distribution indicative of a characteristic of theelectricity supplied to the electrical device; and adjusting, by thevoltage regulator, responsive to the estimated deviant voltage, avoltage level output of the electricity supplied to the one or moreelectrical devices.
 2. The method as recited in claim 1, wherein thevoltage regulator comprises multiple tap settings with each tap settingsupplying electricity with a different voltage level, and whereinadjusting the voltage level output of the electricity supplied to theone or more electrical devices based on the estimated deviant voltagelevel comprises: selecting one of the multiple tap settings to supplyelectricity to the one or more electrical devices based on the estimateddeviant voltage level.
 3. The method of claim 2, wherein selecting oneof the multiple tap outputs to supply electricity to the one or moreelectrical devices based on the estimated deviant voltage level furthercomprises: asserting a decrease in one of the multiple tap settings ifeither a selected estimated deviant voltage exceeds a predeterminedvoltage level derived from a setpoint voltage or an accumulatednonlinear weighted time integral of the selected estimated deviantvoltage exceeds the predetermined voltage level.
 4. The method of claim2, wherein selecting one of the multiple tap settings to supplyelectricity to the one or more electrical devices based on the estimateddeviant voltage level further comprises: asserting an increase in one ofthe multiple tap settings if either a selected estimated deviant voltagefalls below a predetermined voltage level derived from a setpointvoltage, or an accumulated nonlinear weighted time integral of aselected minimum estimated deviant voltage falls below the predeterminedvoltage level.
 5. The method as recited in claim 1, wherein thecomputing of the estimated deviant voltage level responsive to thevarying electrical consumption by the one or more electrical devicescomprises at least one of: (i) estimating a low-pass spectral behaviorof one or more observed voltage time series of the electricity suppliedto the one or more electrical devices, with a spectral cutoff frequencyconsistent with a voltage adjustment decision period; (ii) estimating adispersion or variance of each observed voltage level; (iii) estimatinga first-order envelope of the minimum values of each observed voltagelevel; (iv) applying weighting factors to the estimated dispersionsconsistent with configured confidence specifications thereby estimatinga voltage deviation that will not be exceeded with the specifiedconfidence; (v) computing a forecast minimum for each observed voltageby combining the results of (i), (iii), and (iv) and selecting aforecast minimum voltage from these results; (vi) comparing the selectedforecast minimum voltage against a prespecified voltage bound; (vii)incrementing a nonlinear weighted time integral for the selectedforecast minimum voltage if the forecast minimum voltage is less thanone voltage regulator tap step voltage below the target but greater thana lower voltage bound; and (viii) decrementing a nonlinear weighted timeintegral if the selected forecast minimum voltage approaches the targetvoltage closer than one voltage regulator tap step voltage.
 6. Themethod as recited in claim 1 wherein detecting measurements ofelectricity supplied to the one or more electrical devices via thevoltage regulator comprises: detecting a tap setting and a regulatorload voltage of one or more taps of the voltage regulator.
 7. The methodas recited in claim 1, wherein computing the estimated deviant voltagelevel comprises: filtering the voltage time series of the suppliedelectricity to derive a filtered voltage time series; estimating asmooth delay compensated zero-mean dispersion of the voltage timeseries; and producing a delay compensated smoothed negative peakenvelope of the voltage time series.
 8. A system comprising: anelectronic meter configured to detect measurements of electricitysupplied to one or more devices via a voltage regulator; a processor incommunication with the electronic meter configured to compute anestimated deviant voltage level based on varying electrical consumptionby the one or more electrical devices, the estimated deviant voltagelevel computed based on a predetermined confidence level and themeasurements, wherein the predetermined confidence level corresponds toa probability distribution indicative of a characteristic of theelectricity supplied to the electrical device; and the voltage regulatorconfigured to receive a signal from the processor indicating anadjustment to a voltage level output of the electricity supplied to theone or more electrical devices.
 9. The system as recited in claim 8wherein the voltage regulator includes multiple tap settings with eachtap setting operative to supply electricity with a different voltagelevel, and wherein the processor further comprises: a control mechanismconfigured to generate a signal indicating to select one of theregulator multiple tap settings supplying electricity to the one or moreelectrical devices based on the estimated deviant voltage level.
 10. Thesystem as recited in claim 9 wherein the electronic meter comprises:means for detecting a tap position and a regulator load voltage of oneor more taps of the regulating transformer.
 11. The system of claim 9,wherein the control mechanism configured to select one of the multipletap settings comprises: means for asserting a decrease in one of themultiple tap settings either if a selected estimated deviant voltageexceeds a predetermined voltage level derived from a setpoint voltage orif an accumulated nonlinear weighted time integral of a selectedestimated deviant voltage exceeds the predetermined voltage level. 12.The system of claim 9, wherein the control mechanism further comprises:means for asserting an increase in one of the multiple tap settingseither if a selected estimated deviant voltage fall below apredetermined voltage level derived from a setpoint voltage, or if anaccumulated nonlinear weighted time integral of a selected minimumestimated deviant voltage falls below the predetermined voltage level.13. The system as recited in claim 8 wherein the processor computes thedeviant voltage level by: (i) estimating a low-pass spectral behavior ofeach observed voltage time series of the electricity supplied to the oneor more electrical devices, with a spectral cutoff frequency consistentwith a voltage adjustment decision period; (ii) estimating a dispersionor variance of each observed voltage; (iii) estimating a first-orderenvelope of the minimum values of each observed voltage; (iv) applyingweighting factors to the estimated dispersions consistent withconfigured confidence specifications thereby estimating a voltagedeviation that will not be exceeded consistent with the specifiedconfidence; (v) computing a forecast minimum for each observed voltagefrom the results in (i), (iii), and (iv) and selecting a forecastminimum voltage from these results; (vi) comparing the selected forecastminimum voltage against a prespecified voltage bound; (vii) incrementinga nonlinear weighted time integral for the selected forecast minimumvoltage if the forecast minimum voltage is less than one regulator tapstep voltage below the target but greater than a lower voltage bound;and (viii) decrementing a nonlinear weighted time integral if theselected forecast minimum voltage approaches the target voltage closerthan one regulator tap step voltage.
 14. The system as recited in claim8, wherein the processor is further configured to: process the voltagetime series of the supplied electricity along multiple paths; filter thevoltage time series to derive a filtered voltage time series; estimate asmooth delay compensated zero-mean dispersion or variance of the voltagetime series; and produce a delay compensated smoothed negative peakenvelope of the voltage time series.
 15. A non-transitory computerreadable storage medium comprising instructions which when executed by aprocessor comprise instructions to: detect measurements of electricitysupplied to one or more devices via a voltage regulator; compute anestimated deviant voltage level based on varying electrical consumptionby the one or more electrical devices, the estimated deviant voltagelevel computed based on a predetermined confidence level and themeasurements, wherein the predetermined confidence level corresponds toa probability distribution indicative of a characteristic of theelectricity supplied to the electrical device; and provide a signal toadjust a voltage level output of the electricity supplied to the one ormore electrical devices based on the computed estimated deviant voltagelevel.
 16. The non-transitory computer readable storage medium asrecited in claim 15, wherein the power source has a multiple tapsettings with each tap settings supplying electricity with a differentvoltage level, and wherein the provided signal to adjust the voltagelevel output of the electricity supplied to the one or more electricaldevices based on the computed deviant voltage level comprises:indicating a selection of one of the multiple tap settings to supplyelectricity to the one or more electrical devices based on the computedestimated deviant voltage level.
 17. The non-transitory computerreadable storage medium of claim 16, wherein the instructions furthercomprise instructions to: assert a decrease in one of the multiple tapsettings if either a selected estimated deviant voltage exceeds apredetermined voltage level derived from a setpoint voltage or anaccumulated nonlinear weighted time integral of a selected minimumestimated deviant voltage exceeds the predetermined voltage level. 18.The non-transitory computer readable storage medium of claim 16, whereinthe instructions further comprise instructions to: assert an increase inone of the multiple tap settings if either a selected estimated deviantvoltage fall below a predetermined voltage level derived from a setpointvoltage, or an accumulated nonlinear weighted time integral of aselected minimum estimated deviant voltage falls below the predeterminedvoltage level.
 19. The non-transitory computer readable storage mediumas recited in claim 15, wherein the instructions, which when executed bya processor to compute an estimated deviant voltage level, furthercomprise instructions to: (i) estimate a low-pass spectral behavior ofeach observed voltage time series of the electricity supplied to the oneor more electrical devices, with a spectral cutoff frequency consistentwith a voltage adjustment decision period; (ii) estimate a dispersion orvariance of each observed voltage time series; (iii) estimate afirst-order envelope of the minimum values of each observed voltage timeseries; (iv) apply weighting factors to the estimated dispersionsconsistent with configured confidence specifications thereby estimatinga voltage deviation that will not be exceeded with the specifiedconfidence; (v) compute a forecast minimum for each observed voltagefrom the results in (i), (iii), and (iv) and selecting a forecastminimum voltage from these results; (vi) compare the selected forecastminimum voltage against a prespecified voltage bound; (vii) increment anonlinear weighted time integral for the selected forecast minimumvoltage if the forecast minimum voltage is less than one regulator tapstep voltage below the target but greater than a lower voltage bound;and (viii) decrement a nonlinear weighted time integral if the selectedforecast minimum voltage approaches the target voltage closer than oneregulator tap step voltage.
 20. The non-transitory computer readablestorage medium as recited in claim 15, wherein the instructions furthercomprise instructions to: filter the voltage time series to derive afiltered voltage time series; estimate a smooth delay compensatedzero-mean dispersion of the voltage time series; and produce a delaycompensated smoothed negative peak envelope of the voltage time series.